Study on the Durability of Industrial Waste-MgO Synergistically Cured Silty Sand under Dry and Wet Cycle Conditions

DOI: https://doi.org/10.62517/jcte.202506106

Author(s)

Zhaochang Zhang*, Qiang Wang

Affiliation(s)

School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, Anhui, China *Corresponding Author.

Abstract

Aiming at the common problems of low utilization of industrial solid waste and insufficient performance of pulverized sandy soil roadbase, this study investigated the effect of dry and wet cycles on the mechanical properties of slag-target slag-MgO synergistically cured pulverized sandy soil. The study investigates the impact of dry and wet cycles on the mechanical properties of cured silt soil using unconfined compressive strength tests, mass loss rate measurements, and microscopic characterization techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). It analyzes the changes in hydration products, the bonding strength between soil particles, and the microstructural variations. The results of the study showed that: As the number of wet and dry cycles increased, the mass loss rate of the specimens varied between 14.95% and 18.88%. The strength exhibited a pattern of rising and then falling, with a peak value of 3.90 MPa. the microstructure analysis showed that, with the increase of the number of cycles, the mineral composition of cured silt loam changed, the quartz diffraction peaks were weakened, and the diffraction peaks of the hydration products (e.g., AFt, M-S-H, C-A-H) were enhanced, forming a more compact structure, and improving the structure of cured silty sand, forming a more compact structure and enhancing the strength of the soil. The hydration products of the specimens with high hardener dosage fill the pores, enhance the particle bonding and show higher compressive strength, while the specimens with low hardener dosage have more pores and lower strength due to incomplete hydration reaction or structural damage. The research results can provide theoretical support for the research and development of environmentally friendly slag - calcium carbide slag - MgO cementitious materials and their application in the field of soil reinforcement, such as curing of silty sand.

Keywords

Consolidation of Silty Sand; Wet and Dry Cycles; Unconfined Compressive Strength; Microscopic Properties

References

[1]Zhang Y.L, Zhou L.G., Wang J, et al. Effect of freezing and thawing on mechanical properties of chalky sandy soil and stability of embankment slopes. Journal of Jilin University (Engineering Edition),2019, 49 (05): 1531-1538. [2]Huang Hu, Song C.B., Gao Y., et al. Research on microscopic permeability mechanism of lime-amended sandy soil. Hydropower Energy Science, 2024, 42(12):101-105.DOI:10.20040/j.cnki.1000-7709.2024.20241659. [3]Shi Y., Wang X. Research on the preparation and properties of steel slag-dredged silt mixed cured soil. Green Building Materials, 2020, (11): 8-9. DOI:10.16767/j.cnki.10-1213/tu.2020.011.004. [4]YI Y, GU L, LIU S, et al. Magnesia reactivity on activating efficacy for ground granulated blastfurnace slag for soft clay stabilization. Applied Clay Science, 2016, 126: 57-62. [5]Wang D.X., He F.J., Zhu J.Y. Exploration on the effectiveness and mechanism of CO2 carbonized slag-CaO-MgO reinforced soil. Journal of Geotechnical Engineering, 2019, 41 (12): 2197-2206. [6]Wang D.X., Wang H.W., Zou W.L., et al. Study on durability of activated MgO-fly ash cured silt. Geotechnics, 2019, 40(12):4675-4684.DOI:10.16285/j.rsm.2018.1844. [7]Zhong Y. Q., Cai G. H., Wang J. G., et al. Experimental study on the strength and conductivity characteristics of GGBS-activated MgO carbonized/stabilized zinc contaminated soil. Journal of Geotechnical Engineering, 2021, 43(S2):221-224. [8]Chen J.H., He Y.Y., HU Yafeng. Mechanical property test of granulated blast furnace slag-magnesium oxide cured Lianyungang soft soil. Journal of Forestry Engineering, 2019, 4(02):133-138.DOI:10.13360/j.issn.2096-1359.2019.02.021. [9]Ren K.B., Wang B., Li X.M., et al. Dry and wet cycle effects on mechanical properties of soil sites under low stress level. Journal of Rock Mechanics and Engineering, 2019, 38(02):376-385.DOI:10.13722/j.cnki.jrme.2018.0988. [10]Kong X.H., Liang Y.P., Zhang J.G., et al. Experimental study on magnesium oxide-desulfurization gypsum-steel slag joint curing of dredged substrate. Journal of Chongqing Jiaotong University (Natural Science Edition), 2023, 42 (12): 61-69. [11]Yi Y, Zheng X, Liu S, et al. Comparison of reactive magnesia-and carbide slag-activated ground granulated blastfurnace slag and Portland cement for stabilisation of a natural soil. Applied Clay Science, 2015, 111: 21-26.